Soft tissue massage, including deep friction or cross fiber massage, has been known and practiced manually, that is, by hand, for some time. Friction massage is different from the superficial massage given in a longitudinal direction parallel to the vessels. Early pioneers of friction massage working in the 1930's and '40s include David Mennell and James cyriax. Mennell advocated the use of specific massage movements called "friction" movements for conditions of inflammation and pathological deposits, as well as for recent ligament and muscle injuries. Cyriax later utilized a technique which he coined "deep friction massage" to reach the musculoskeletal structure of ligament, tendon and muscle and provide therapeutic movement over a small area.
The purpose of deep massage or the mobilization of soft tissue is to maintain the mobility within soft tissue structures of ligament, tendon, and muscle, and to break down and/or prevent fibrous adhesions, commonly known as scar tissue, from forming. Soft tissue mobilization, when performed properly, is performed deep into the soft tissue and, in cross fiber massage, is applied transversely, that is, not in a longitudinal direction but in a direction across the tissue fibers, to the specific fibrotic soft tissue involved.
The biological healing of soft tissue injury is similar in muscle, tendon, and ligament. When soft tissue is stressed beyond its biomechanical yield strength, microtearing of the soft tissue under stress typically occurs. The human body's normal response to the microtearing of collagen is inflammation. Scar tissue typically lays down in a threedimensionally random fashion. This randomness can begin to affect the function (contractility and extensibility) of the surrounding tissues, which have a more uniform structure. Any loss of function may result in a reaggravation of the soft tissue during normal use and a vicious cycle of microtearingin-fiammation-scarring.
The scientific reasons why soft tissue mobilization is successful are not fully understood. Yet, because this modality involves pressure and movement directed across or against the scar tissue, most theories are based on the effect of motion on healing tissue. It is well accepted today that early motion of injured tissue results in repair with reduced scar tissue formation or more improved alignment of the fibrosis and the soft tissue structure. In the early stages of healing, scar tissue is not as strong as in later stages, and it is thought that the remodeling phase of the inflammatory response depends on mechanical stimuli. Cyriax stated that transverse motion across the involved tissue and the resultant traumatic hyperemia were the chief healing factors. Cyriax further stated that moving across the fibers at a right angle would not injure the normal healing tissue but would prevent the formation of or cause the break down of abnormal scar tissue. Transverse friction moved the involved tissue, Cyriax held, while longitudinal friction affected the transportation of blood and lymph through the blood vessels.
In the acute stage of an early lesion within soft tissue, collagen (scar tissue) is immature. During the first 4 or so days, fibroblasts lay down a gel-like substance, but it takes up to 2 weeks for mature cross-links of the collagen to form. In the early stage of an acute lesion, it is reasonable to use only a light friction pressure. Light friction is primarily used to aid in the promotion of normal orientation of collagen, to maintain the mobility of the soft tissue, and to thereby prevent future scar tissue adhesions from forming. In the chronic stages, a deeper, stronger pressure is necessary.
To achieve mobilization of soft tissue, after the involved fibrotic soft tissue (muscle, tendon, or ligament) is located, typically through a combination of the practitioner's review of the patient's history and functional and physical diagnostic testing of the suspected fibrotic soft tissue areas, a practitioner can use a reinforced finger, i.e., middle finger over forefinger, that is just large enough to apply deep pressure across the injured fibrotic soft tissue. At times, because of the increased amount of pressure that must be applied or due to the density of the tissue being treated, it is advisable for the practitioner to employ a separate hand instrument. Such an instrument is also beneficial in preventing injury to the practitioner due to the prolonged period of time in which the increased pressure must be applied to the soft tissue areas of the patient.
Various tools are known for use in performing superficial massage which is given in a longitudinal direction parallel to the blood vessels to enhance blood circulation and the return of fluids to those areas of living subjects, particularly humans. For example, Courtin, U.S. Pat. No. 4,590,926, discloses a hand-held massager intended to provide effective massaging of various body parts.
Weeks, U.S. Pat. No. 1,769,872, describes a massage implement having a top surface, curved side surfaces, and a bottom surface. The curved sides and bottom are adapted to be held in the palm of the hand with the fingers arranged near a sharpened end, while the blunt end of the device is received in the palm of the hand. The top surface of the Weeks device is provided with a series of undulations intended to give the body parts massaged the same effect as though a manual massage is being performed. This device is primarily intended to be used about the face and neck.
Various other tools which have been disclosed in the prior art for use in massage include U.S. Pat. No. Des. 262,908; U.S. Pat. No. Des. 263,077; U.S. Pat. No. Des. 264,754; U.S. Pat. No. Des. 272,090; U.S. Pat. No. Des. 285,116; U.S. Pat. No. Des. 288,847; U.S. Pat. No. Des. 317,204; and U.S. Pat. No. Des. 323,035.
More recently, Warren Hammer, D.C., taught, inter alia, the use of a small rubber-tipped hand tool (commonly referred to as a "T-bar") to perform cross-friction massage of, particularly, plantar fascitis, plica, and patellar ligament lesions. See, Functional Soft Tissue Examination and Treatment by Manual Methods: The Extremities (Aspen Publications, Inc., Copyright 1991).
There continues to remain a need, however, for instruments of improved ergonomic design to better assist a practitioner not only in the treatment of fibrotic soft tissue by way of soft tissue mobilization therapies, but in its diagnosis as well.